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Claude Opus 4.6 vs GPT-5.6 Terra

GPT-5.6 Terra leads the LLM Stats Score 51.2 to 45.1. GPT-5.6 Terra is 2.2x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

GPT-5.6 Terra leads the overall LLM Stats Score 51.2 to 45.1, ranking #12 overall.

In the 5 individual benchmarks reported for both models, GPT-5.6 Terra wins 5; this is a narrower head-to-head signal than the composite indexes.

On price, GPT-5.6 Terra is roughly 2.2x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.6 Terra also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Opus 4.6

  • you want predictable pricing at $5.00/M input and $25.00/M output

Choose GPT-5.6 Terra

  • overall performance matters — it scores 51.2 and ranks #12 on LLM Stats
  • your work emphasizes coding and agents — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 5 of 5 exact shared results
  • cost matters — it's about 2.2x cheaper per token
  • you process long inputs — it offers a 1,050,000 token context window
  • you want the most recent training data — it shipped Jul 2026

At a glance

The differences that matter most.

Core performance indexes
45.1
#31
51.2
#12
45.6
#27
49.4
#16
33.0
#34
42.4
#7
28.0
#36
37.8
#10
Cost, coverage & limits
Benchmark wins
0 of 5
5 of 5
Input price
$5.00 / M
$2.00 / M
Output price
$25.00 / M
$12.00 / M
Context window
1,000,000
1,050,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

6 shared
Index
Claude Opus 4.6
GPT-5.6 Terra
40.0#14
32.3#57
27.0#38
29.7#30
25.2#34
30.0#17
24.4#15
25.9#12
22.8#54
30.2#28
1 more shared indexes
11.1#16
14.7#9
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

27 reported for Claude Opus 4.6 · 45 for GPT-5.6 Terra

5 shared

Claude Opus 4.6 outperforms in 0 benchmarks, while GPT-5.6 Terra is better at 5 benchmarks (BrowseComp, GPQA, Graphwalks BFS >128k, MMMU-Pro, MRCR v2 (8-needle)).

GPT-5.6 Terra significantly outperforms across most benchmarks.

Fri Sep 04 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT-5.6 Terra costs less

For input processing, Claude Opus 4.6 ($5.00/1M tokens) is 2.5x more expensive than GPT-5.6 Terra ($2.00/1M tokens).

For output processing, Claude Opus 4.6 ($25.00/1M tokens) is 2.1x more expensive than GPT-5.6 Terra ($12.00/1M tokens).

In conclusion, Claude Opus 4.6 is more expensive than GPT-5.6 Terra.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Fri Sep 04 2026 • llm-stats.com
Anthropic
Claude Opus 4.6
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
OpenAI
GPT-5.6 Terra
Input tokens$2.00
Output tokens$12.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

GPT-5.6 Terra accepts 1,050,000 input tokens compared to Claude Opus 4.6's 1,000,000 tokens. Both models can generate responses up to 128,000 tokens.

Anthropic
Claude Opus 4.6
Input1,000,000 tokens
Output128,000 tokens
OpenAI
GPT-5.6 Terra
Input1,050,000 tokens
Output128,000 tokens
Fri Sep 04 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 4.6 and GPT-5.6 Terra support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Opus 4.6

Text
Images
Audio
Video

GPT-5.6 Terra

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Opus 4.6

Proprietary

Closed source

GPT-5.6 Terra

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.6 was released on 2026-02-05, while GPT-5.6 Terra was released on 2026-07-09.

GPT-5.6 Terra is 5 months newer than Claude Opus 4.6.

Claude Opus 4.6

Feb 5, 2026

7 months ago

GPT-5.6 Terra

Jul 9, 2026

1 months ago

5mo newer

Knowledge Cutoff

When training data ends

GPT-5.6 Terra has a documented knowledge cutoff of 2026-02-16, while Claude Opus 4.6's cutoff date is not specified.

We can confirm GPT-5.6 Terra's training data extends to 2026-02-16, but cannot make a direct comparison without Claude Opus 4.6's cutoff date.

Claude Opus 4.6

GPT-5.6 Terra

Feb 2026

Provider Availability

Claude Opus 4.6 is available from Anthropic. GPT-5.6 Terra is available from OpenAI.

Claude Opus 4.6

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

GPT-5.6 Terra

openai logo
OpenAI
Input Price:Input: $2.00/1MOutput Price:Output: $12.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against Claude Opus 4.6 and GPT-5.6 Terra side-by-side, then vote on the output you prefer.

Claude Opus 4.6
✓ Preferred
GPT-5.6 Terra
Open in Playground

FAQ

Common questions about Claude Opus 4.6 vs GPT-5.6 Terra.

Which is better, Claude Opus 4.6 or GPT-5.6 Terra?

GPT-5.6 Terra leads the LLM Stats Score 51.2 to 45.1. Claude Opus 4.6 is made by Anthropic and GPT-5.6 Terra is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Opus 4.6 compare to GPT-5.6 Terra in benchmarks?

Claude Opus 4.6 scores Vending-Bench 2: 100.0%, AIME 2025: 99.8%, Tau2 Telecom: 99.3%, Graphwalks parents >128k: 95.4%, Tau2 Retail: 91.9%. GPT-5.6 Terra scores Connectors: 100.0%, HealthBench Consensus: 95.1%, Search and Function-Calling: 94.6%, GPQA: 92.9%, Capture-the-Flag Challenges (Internal): 91.8%.

Is Claude Opus 4.6 cheaper than GPT-5.6 Terra?

GPT-5.6 Terra is 2.5x cheaper for input tokens. Claude Opus 4.6 costs $5.00/M input and $25.00/M output via anthropic. GPT-5.6 Terra costs $2.00/M input and $12.00/M output via openai.

What are the context window sizes for Claude Opus 4.6 and GPT-5.6 Terra?

Claude Opus 4.6 supports 1.0M tokens and GPT-5.6 Terra supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 4.6 and GPT-5.6 Terra?

Key differences include LLM Stats Score (45.1 vs 51.2), context window (1.0M vs 1.1M), input pricing ($5.00 vs $2.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.6 and GPT-5.6 Terra?

Claude Opus 4.6 is developed by Anthropic and GPT-5.6 Terra is developed by OpenAI.